I made an extra contribution to my HSA in 2019. Where do I put this amount on 2019 tax return

Not sure what you mean by "extra contribution". Do you mean an a contribution in addition to what was contributed by your employer (assuming your employer contributes something) by sending money directly to your HSA custodian (but such the total is less than the statutory limit) or do you mean an EXCESS contribution, an amount greater than the maximum the tax code permits you to contribute. The answer to your question is very different depending on what you mean.

The contribution is reported here:

• Down the left side of the screen, click Federal.
• Across the top of the screen, click Deductions & credits.
• Scroll down to Medical.
• Click on Start/Revisit.
• Click on HSA, MSA contributions.

See also this TurboTax Help.